Update Project Version to 0.91.0

Author: beomki-yeo

CMakeLists.txt

@@ -6,7 +6,7 @@
 
 # Set up the project.
 cmake_minimum_required(VERSION 3.11)
-project(detray VERSION 0.87.0 LANGUAGES CXX)
+project(detray VERSION 0.91.0 LANGUAGES CXX)
 
 # Set up the used C++ standard(s).
 set(CMAKE_CXX_STANDARD 20 CACHE STRING "The (host) C++ standard to use")